Our research is concerned with basic mechanisms of the regulation and control of cell growth, with particular reference to wound healing and neoplasia. We have isolated and partially purified several fractions of growth factors of biological origin which promote the growth of cells of mesodermal origin. The mesodermal growth factors enhance the development of fibroblasts at the wound edge in organ cultures of corneas. It has been proposed that polypeptide growth factors, including those we are studying, may constitute a new class of hormones which are the primary factors for control of growth in different organs or tissues of the intact animal. We will investigate the role of these growth factors in neo-vascularization, potentiation of the healing of corneal grafts, and protection of cells against injuries of various kinds - freezing, mechanical, and chemical (toxic). In preliminary studies we have found that mesodermal growth factor preserves the viability of corneas stored by cryopreservation and protects the cells from injury by toxic levels of DMSO. Basic information which we are obtaining with the study of these growth factors is giving us an increasing understanding of many cellular mechanisms involved in the regulation of cell growth. This information may provide possible solutions or aid in the treatment of certain clinical conditions. For example, some of our preliminary data may explain the poor wound healing found in diabetes and during treatment of corneal wounds by certain corticosteroids.